Evidence of a new Tomato yellow leaf curl virus in Japan and its detection using PCR

A new isolate of Tomato yellow leaf curl virus (TYLCV) has been identified from tomato plants in Kochi Prefecture in Japan and designated TYLCV-[Tosa]. The complete nucleotide sequence of the isolate was determined and found to consist of 2781 nt. In phylogenetic analyses of entire nucleotide sequences, TYLCV-[Tosa] was delineated as a single branch and was more closely related to TYLCV-[Almeria] than TYLCV isolates Ng, Sz, or Ai reported in Japan, which had spread since 1996. Isolate TYLCV-[Tosa] is suggested to be a newly introduced, novel isolate of TYLCV that dispersed into Kochi Prefecture. In addition, a rapid method using the polymerase chain reaction to separate TYLCV isolates into four genetic groups was established. This method would be useful for reliable diagnosis based on genetic differences among isolates of TYLCV.The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession numbers AB192965 and AB192966     

Vertical distribution of leaf blast lesions in mixtures of rice cultivar Sasanishiki and its resistant near-isogenic line

The vertical distribution of leaf blast lesions caused by the fungus Pyricularia grisea was studied to estimate the degree of leaf blast suppression in rice multilines in experimental paddy fields for 4 years. Leaf blast in 1 : 1 and 1 : 3 mixtures of susceptible rice cultivar Sasanishiki and its resistant near-isogenic line, Sasanishiki BL7, developed slower than that in pure stands of Sasanishiki. The average distance of lesions on leaves from the ground in the 1 : 3 mixtures was significantly lower than that in the pure stands at the end of leaf blast epidemics (at booting stage). This result shows that the distribution of leaf blast lesions in the upper layer differs between the susceptible pure stands and the 1 : 3 mixtures at the end of leaf blast epidemics.     

Obstructive nephropathy induced with DL-potassium hydrogen tartrate in F344 rats

We experienced obstructive nephropathy in F344 rats treated with DL-potassium hydrogen tartrate (PHT) in a 13-week oral repeated dose toxicity study. Six-week-old male and female F344/DuCrj rats were fed a diet containing up to 2.0% PHT for 13 weeks. Microscopical findings including irregular dilation of the distal tubule lumen, foreign body giant cells, inflammatory cell infiltration, and regeneration of renal tubules were observed focally or multifocally in the renal cortex and/or medulla in the 0.5% and higher dosage groups of both sexes. The severity of these lesions increased in a dose-dependent manner. In the urinalysis, an increase in protein and white blood cells or the concentration of tartaric acid was detected in the 0.5% PHT and higher dosage groups of both sexes or males, respectively, though conventional blood biochemical analysis did not indicate failure of renal function. These results indicate that the PHT induces obstructive nephropathy in rats. There were no other treatment-related changes in other organs.     

Effects of vertically transferred 3,3',4,4',5-pentachlorobiphenyl on gene expression in the ovaries of immature Sprague-Dawley rats

We have previously shown that 3,3',4,4',5-pentachlorobiphenyl (PCB-126) vertically transferred from dams potentially exerts a direct effect on the ovaries of offspring and adversely affects female puberty. To investigate its toxicological targets in ovarian tissues, mRNAs encoding representative peptides that regulate follicular development in granulosa cells, theca cells, and oocytes were quantified using ovaries collected on postnatal days (PND) 5, 15, and 24 from the offspring of dams administered oral doses of 0, 1 or 3 microg/kg PCB-126 starting 2 weeks prior to mating and continuing until 20 days after delivery. Quantification using the real-time RT-PCR method revealed that PCB-126 lowered the amounts of mRNAs that encoded the inhibin alpha- and inhibin/activin beta A-subunits from PND 15 onwards; the amounts of mRNAs for inhibin/activin beta B-subunit, follicle-stimulating hormone (FSH) receptor, and aromatase on PND 15; and the amounts of luteinizing hormone receptor mRNA on PND 24 compared with those of the age-matched controls. In contrast, no differences were noted for mRNAs encoding c-kit, growth differentiation factor-9, bone morphogenetic protein-15, or kit ligand for any of the age groups examined. The serum FSH level on PND 24 was higher than that in the control. Since the earliest effects on the mRNAs in the rat ovaries were observed in those expressed in the granulosa cells of the growing follicles after the antral follicles had developed, molecules in granulosa cells but not in oocytes during the early stages of the antral follicles might be the primary targets of vertically transferred PCB-126.     

Exploration of the antibacterial proteins in pearl oyster <Emphasis Type="Italic">Pinctada fucata</Emphasis> induced by bacterial inoculation

The aim of this research was to characterize immune-related antibacterial substances from pearl oyster Pinctada fucata induced by bacterial invasion. Bacteria inoculation was performed by injecting 0.1 ml of 1.0 × 10¹² colony-forming units/ml Vibrio parahaemolyticus into adductor muscle. Acidic extracts were prepared with 0.1% trifluoroacetic acid from different tissues after 8 h of injection, and antibacterial activity against V. parahaemolyticus was determined via the microdilution broth method. The acidic extracts from gills of inoculated oysters (AEg) showed stronger antibacterial activity than those from non-inoculated ones. Based on this result, antibacterial proteins were purified from AEg via two-step gel filtration chromatography, followed by high-performance liquid chromatography using a TSkgel G3000 column. Protein components were analyzed by both sodium dodecyl sulfate and native polyacrylamide gel electrophoresis. As a result, two antibacterial proteins, APg-1 (with a molecular mass of approximately 210 kDa) and APg-2 (of approximately 30 kDa), were obtained from AEg. Matrix-assisted laser desorption/ionization time of flight mass spectrometry analysis and partial amino acid sequences revealed that these proteins might be novel antibacterial proteins. These results indicate that antibacterial proteins are potentially upregulated in the gill of pearl oysters or released therefrom for defense against bacterial invasion.     

Rheological Properties of Starch Gels from Wheat Mutants with Reduced Amylose Content

Wheat lines with reduced amylose content were recently produced by single and double mutation from a low‐amylose line, Kanto 107. They are appropriate for clarifying the influence of amylose content on starch gel properties because of their similar genetic background. When measured using the concanavalin A method (ConA), the total amylose content of isolated starches from Kanto 107 and three mutants (K107Afpp4, Tanikei A6599‐4, K107Wx2) was 24.8, 18.5, 7.1, and 1.7%, respectively. Results of differential scanning calorimetry (DSC) showed that the difference in amylose content strongly affected gelatinization conclusion temperature and enthalpy. We prepared 30 and 40% starch gels and measured their dynamic shear viscoelasticity using a rheometer with parallel plate geometry. Compressive and creep‐recovery tests were conducted under uniaxial compression. The storage shear modulus correlated highly with the amylose content of starch in 30 and 40% starch gels. The creep‐recovery test showed a clear distinction in creep curves among starch samples. When the compressive force required for 50, 80, and 95% strains was compared, starch gels with lower amylose content showed lower compressive force at 50% strain. Waxy starch gel (K107Wx2) showed higher compressive force at strain >80% than other samples due to its sticky property.     

Rheological Properties of Fermented Rice Flour Gel

To clarify the rheological properties of fermented rice noodle (sour mifen) produced in South China, we studied the mechanical properties of gels made from fermented and nonfermented (control) rice flours using static tensile testing, two-bite testing, and dynamic viscoelastic measurement. Rheological measurement under large deformation showed that retrogradation in fermented rice gel proceeded more slowly than in nonfermented rice gel. Lower hardness and brittleness and higher cohesiveness and resilience (degree of recovery) for gels made from fermented rice flour demonstrated that the gel was less firm but more elastic and flexible. Storage moduli of both types of gel increased with time, but the starch retrogradation was suppressed for fermented rice gel. Fermented rice gel exhibited higher resilience and lower rigidity than nonfermented gel, thus the gel stability improved. The chemical analysis of both starches suggests that the partial hydrolysis of amylopectin occurred during the fermentation process.     

宁夏引黄灌区农田排水沟渠水生植物物种多样性

为探索宁夏引黄灌区农田排水沟水生植物物种组成和多样性,采用样方调查法在灌区农田选取典型支沟、斗沟和农沟,并在每条沟渠布设上、中、下游断面,断面上设置样方大小进行退水沟渠水生植物物种种类、数量、多度、盖度调查。结果表明：宁夏引黄灌区排水沟水生植物由11个科,13个属,20个种组成,其中,芦苇、藨草、水莎草、香蒲、龙须眼子菜和浮叶眼子菜是分布较广的优势种。群落垂直分层明显,但以芦苇及其伴生种组成的挺水群落多见。灌区农田排水沟各层次植物种类分布和多样性指数差异较大,表现为农沟>斗沟>支沟。水位和流速是影响沟渠水生植物形态及分布的主要因素。农沟中水流速度较慢,生长环境稳定,有利于多种植物的繁殖,为科学合理布局优势物种富集农田排水中的养分,以达到控制农田非点源污染目的提供了可能。     

Determination of 15 isoflavone isomers in soy foods and supplements by high-performance liquid chromatography

Soy isoflavone is the generic name for the isoflavones found in soy. We determined the concentrations of 15 soy isoflavone species, including 3 succinyl glucosides, in 22 soy foods and isoflavone supplements by high-performance liquid chromatography (HPLC). The total isoflavone contents in 14 soy foods and 8 supplements ranged from 45 to 735 μg/g and from 1,304 to 90,224 μg/g, respectively. Higher amounts of succinyl glucosides were detected in natto, a typical fermented soy product in Japan; these ranged from 30 to 80 μg/g and comprised 4.1-10.9% of the total isoflavone content. In soy powder, 59 μg/g of succinyl glucosides were detected, equivalent to 4.6% of the total isoflavone content. These data suggest that the total isoflavone contents may be underestimated in the previous studies that have not included succinyl glucosides, especially for Bacillus subtilis -fermented soy food products.     

Effect of the long-term application of anaerobically digested residual slurry on methane emissions in a rice paddy field

ABSTRACT

The anaerobic digestion of livestock manure is an environmentally compatible technology used for the production of renewable energy. Anaerobically digested residual slurry has been used worldwide as a liquid fertilizer in both upland and paddy fields. However, a controversial question remains as to whether the application of slurry to rice paddy fields increases methane emissions; although methane is one of the most prevalent greenhouse gases, little is known about the effects of the long-term application of residual slurry on methane emission. In this study, we repeatedly applied slurry to a paddy field for six years at different application rates (10, 15, and 20 g N m^?2 based on ammonium-nitrogen content). At the fifth and sixth years of application, we evaluated the effect in terms of methane flux and soil total carbon content. The effect of the long-term application of the slurry (10 g N m^?2) on grain yield was equivalent to that of chemical fertilizer (10 g N m^?2). The application of the residual slurry was likely to increase the cumulative methane emissions during rice growing season in both 2006 and 2007. On the other hand, we observed that soil total carbon did not accumulate significantly in the soil. Thus, we cannot rule out the potential risk of additional methane emissions caused by the application of the residuary slurry to paddy fields.